1. Field of the Invention
The present invention relates generally to vehicle propulsion, and more specifically to human-powered vehicle propulsion, such as human-powered propulsion of a water vehicle.
2. Discussion of the Related Art
Kayakers and other boaters exhibit a wide range of skill levels, from the recreational kayaker to the professional competitor. Kayaking enthusiasts pursue their sport in a variety of settings, including creeks, rivers, and the ocean. Each of the settings presents unique challenges to the kayaker.
In order to kayak effectively, it is essential that the kayaker be able to effectively control the kayak with a minimum of effort; this is no less true for the recreational kayaker than it is for the expert. The essential element in kayak control is the kayak paddle. A kayak paddle that the user can easily and efficiently employ will greatly facilitate control of the kayak.
Kayak paddles include a single elongated shaft and two flattened blade portions, which may be either integral with the shaft or coupled thereto. The paddle is usually made of some suitably rigid material such as carbon fiber, wood, aluminum, or plastic. Low weight and sufficient strength to resist the forces imposed upon the paddle are important considerations in the manufacture of paddles.
To use a kayak paddle one grips and supports the shaft with both hands, generally perpendicular to the longitudinal axis of the kayak. A blade is inserted in the water near the side of the boat at a point in front of the user. The blade is then pulled backward approximately parallel to the longitudinal axis of the kayak, by backward pressure exerted through the hand closest to the blade in the water, while forward pressure is exerted through the other hand. When the blade has been pulled back to a point beside or just behind the user, it is removed from the water with an upward motion and the opposite blade is inserted in the water in front of the user. The sequence of motions is repeated, creating forces that propel the boat forward through the water. Subtle differences in the amount of force applied and the direction in which it is applied with each stroke are used to steer the kayak and keep it on course.
In order to paddle effectively, the kayaker must be able to hold the paddle continuously aloft with both hands while simultaneously twisting, rotating and raising/lowering the blades. This requires some amount of physical strength and coordination.